ProPublica and the Virginian-Pilot filed a lawsuit Friday in federal court against the U.S. Department of Veterans Affairs, accusing the agency of stonewalling requests for documents under the Freedom of Information Act.

The lawsuit, ProPublica’s second against the VA in two months, seeks a preliminary injunction compelling the government to immediately release correspondence about Agent Orange, an herbicide used to kill vegetation during the Vietnam War, including documents sent to and received by Dr. David Shulkin, the VA’s undersecretary for health. Shulkin has been nominated to be VA secretary by President-elect Donald Trump.

ProPublica and the Pilot have been reporting about Agent Orange for 18 months, documenting ongoing effects on veterans and their families. The FOIA requests at issue in today’s lawsuit date back to May and September 2015.

As the news organizations have reported, the VA faces a number of imminent decisions about whether to cover certain groups of veterans who claim they were exposed to Agent Orange, as well as certain diseases that research has shown to be linked to the chemical mixture.

Exhibits attached to the lawsuits show how the FOIA requests submitted by the news organizations were subjected to one delay after another. ProPublica and the Pilot sought help from the VA’s Office of General Counsel, the agency’s chief information officer, as well as the Office of Government Information Services, also known as the FOIA ombudsman. Those efforts were not met with success.

“Repeated pleas to the VA to process two FOIA requests, which now have been pending for 618 days and 506 days, respectively, have been utterly disregarded. Indeed, ProPublica and The Virginian-Pilot have done everything short of turning cartwheels in front of VA’s headquarters to draw attention to these requests,” the legal memorandum in support of a preliminary injunction said.

Without immediate disclosure of the records, “ProPublica and The Virginian-Pilot will suffer irreparable injury with respect to their ability to timely and thoroughly report, for the public benefit, on these urgent and current issues concerning Agent Orange and dioxin,” ProPublica senior reporter Charles Ornstein said in a declaration attached to the motion for a preliminary injunction.

“We continue to have intense interest in educating the public, including our readers in Congress, the administration, the military, and the veteran community concerning this subject matter,” Ornstein wrote. “And we continue to see intense interest in this subject matter from our readership as well as those who have completed our surveys or provided information through our crowdsourced efforts.”

The VA did not respond to a request for comment. In response to the first lawsuit, filed last month, the agency said it does not comment on pending litigation. It also said, “VA strives to process FOIAs on a first-in, first-out basis. Generally, requests are placed on one of two tracks: simple or complex. Complex requests, by definition are more laborious and may require more time to process.”

In its first lawsuit, ProPublica sought correspondence between various VA officials and scientist Alvin Young, who has guided the stance of the military and VA on Agent Orange and whether it has harmed service members. The suit also sought internal correspondence about any contracts awarded to Young or his consulting firm.

News organizations are increasingly turning to lawsuits to seek records they requested under FOIA, according to a recent analysis by the FOIA Project.

Today’s lawsuit, filed in U.S. District Court in Washington by Seth Watkins of the law firm Adduci, Mastriani & Schaumberg, in Washington, D.C., seeks an order compelling the VA to produce the records and pay its attorney’s fees.